The present invention relates generally to an adjustable hinge, and more particularly, to an adjustable hinge connecting a backrest member to a seat member of a seat, especially a seat of an automotive vehicle.
Automotive vehicle seats having a backrest that can be adjusted to a plurality of positions with respect to the seat member to accommodate the comfort of the user are becoming increasingly popular. Many types and varieties of adjustable hinges are currently employed in automotive vehicle seats. However, these adjustable hinges are either complex and expensive or, if simply constructed, they are not durable and usually fail to perform adequately. Such adjustable hinges tend to bind and warp when secured to the vehicle seat thereby hindering smooth tilting of the backrest with respect to the seat member.
U.S. Pat. No. 3,837,705 discloses a mechanism for tilting the backrest of a secretarial chair with respect to its seat. The adjusting mechanism of this patent includes a slider member having projecting portions fitted into helical grooves formed in a hub that is attached to the backrest so that when the slider member is moved axially its projecting portions move through the helical grooves causing the backrest to tilt. The slider member is restrained from rotation by a pair of fixed pins disposed in notches formed in the slider member. This adjusting assembly requires numerous components, is complex, and is not designed for use in an automobile vehicle seat.
It is the general object of this invention, therefore, to provide an adjustable hinge for an automotive vehicle seat having an axially movable control member operable to impart rotational movement to the backrest of the vehicle seat.
It is another object of the present invention to provide an adjustable hinge for an automotive vehicle seat characterized in that it comprises few components and is easily and inexpensively assembled.